Pneumatic tool.



A PATENTED DBC. 18 H. lA. R'. PRINDLE &- J. U.' ADOLPH.

2 SHEETS-SHEET 1y j j 1 PNEUMATIG TooL. APP-LIOATI'ON FILID 00T 10 1904.

Elu

56 v an external thread,- and the part Hisscrewedf PENNSYLVANIA; I 1 y UMATlCT-QL- lowing isfa full, clear, andfexaet description- Beit known that we, HARoLnA.

` DLE and JQHN- U Amun, f 0f Pnnaduphm, in the 'county' of Philadelphialand jStat-e of Pennsylvania`, have invented f a "certain new and useful Improvementf*in flneumatio Tools andl -we do ,hereby declarethat A,the :fol-

thereof7 reference being yhadt'o-the accompaA nyingdfawingsawhwhs .r fFigures 1 and 2 ar longitudinal sectional Vviews ofla; tooljemboflying our invention,

showing the'parts in di A erent positions;- and- Figs'. 3, 4', and 5: are: 1:espectiv'ely sectional l obje'ct offou'l--nvention hasbeenyto Y provide afpneumaticf tool mv-.whichthere-v Shall be wheel-exhaust during' the @miie "down or: working'stfroke of'the hammer, and

(erich exhaust on y, the-, return lst'roke, except as Ait is to cushion-thefhammer yin which l the valve shallbe held bothIupand down byv sition';` iniwhichfthe valve shall be strong andnot easily broken, fand in which a' veryrapid` 1 strokeis possible, vbeycau'sefthe fv'alve 1s actui "i provide 'a vs he 1A, p'rovi d'ed which is mounted ay hamm Y beingpreferably in the for rated in both directions vby'jliveA andto such endsfour invention consists"invthepneuV matic tool hereinafterspeeilied.'" L In carryin "our invention. intoV ifactic'e 'we 'with abolie-B, in', ,thehammer of La' plain cylinder. 'A tool D is mounted`l` inthe lower end:

i ofthe shell Ain any desiredz-marfi'ner;H AIn the formwhich we have villustrated.thetffol D isv provided with an'end'orshank d, that fits-af passage e -in the shell A, 'such" pas' sage per-1 1 mitting the shank to extendup Whe'reit can be struck` by thehammer;` 4Acollar e on the f tool-shank 'properly'positionsfthe tool. -A

cap 'Fv is screwed on the lower-end-of the shell and compresses' a spring `:G," t' liat surrounds the tool, against the said collar and tends to hold'thetool up in position tore#A ceive a blow from the hammerg* gU on the mointed in any desired manner. Aswe have illustrated it the shell is'providedwith Iupon said 'thread'.l A disk lis-'seated upon the vupper end ofthe shell, dowel-pins being disk a valve-casin K'zismo'unted, the said diameter at lts lower endanda boref"k of smaller diameter extending v.through to its opposite. end." The handle H is provided -v vprovided:to pieventtlie the disk with l'efeleIlCO the shell,-and upon said-"5 5 casing being provi ed With'a-bore k of 'larger with an interior surface that'bears upon f thevalveleasingv and force the` disk against --theshe1i1-rhs-handlesNeeded wah an ,air-passa enh', which is governedby a-;bal.v

anced `va ve L,;the latter beingn the form` of a plug sliding in a passage h in the handle. The plug isnor'mallyf raised by a, vspringM,

seated beneath itin the passagel h2, and such plug extends up into; convenient 'reach of. the i -thumbof'the operatori Theplugis rovided with *av neck or groove l' normally a ove the dssa/ge h. A passage h* beside the passage 'communicates with the neck l when t shifting the-"valveso `that 'its, neck is op'- p'osite the iair-passagesair canpass through the said passageslto reach 'theval've-casing.'

'Whenvthe v alveisraised so that its neck 1sv not coincidentwiththe passages, the flow of air is revented."

Wit thevalve-casingismountedavalve N, having'a-larger: cylindricalortion n, that .fits the larger and lower bore, in the-valvecasin'g and that is providedwth'an annular groove n lin its periphery, Whichlatter in thel upper positionwof the valve is adapted tocom- 'munica't'e with aA passage, Ogformed in the valve-casing, the said Lpassagel O` extending, l

4down to thebottom ofthe central or piston 'bore B of the 'shell-A to permit air .to reach the underside ofthe hammer.- The groove 'n/ co'nnectsby 'a hole orho'les with af central passage I n? -in the 'valve, which plas sage extends'- through the valve to its up erend, so

passage 'P communicatesr by the passa ev p with the upper end of the central-bore o `the shell to permit the air to reach the upper sideof the piston. y 'Apreferably small'pasf ICO los

sition.

s ageR-aflords communication between the 'I live-'air passage h? and 'the lower| portion of the bore`fk, the exit of such passage' being at such level that the portion nS-of the -faceof the piston covers such exit in the lowest osi'- tion of the valve. A passage S extends om the upper face of the disk I to a point in the bore B just above the pistonin its lowest po- An exhaust-passage T extends, from a point in the lower part of the bore B to an exit tothe outer air at any desired point. A

assage U connects the upper end of the ar er borerwith theouter air.

n the o eration of'the above-illustrated hemmen tiieair, b'y-means'ofthe passages P and Y ,reaches the up er side of the hammer and orces the latter oWn upon the`tool,the air in advance of the hammer exhausting through the passage T and (after the hammer has passed the:

entrance to such passage) exhausting through the passages O and U to the outer air. It

will be seen that we provide a'free exhaust for the air through the working stroke of the hammer and that no force is lost by cushioning. IlVhen the piston passes the entrance to the passage S, the liveair enters such passage and, reaching the under side of the valve 1n directly beneath t e valve.

thus sustained in its'uppe'r position (as well as in its lower position) by llve air, and leakage cannot' cause it to be displaced. The

raising of the valve to its upper position lcausesA the groove n to coincide with the passage 0, and live air can thus pass through the `bore 'az'in the valve-stem, through the holes n in the larger portion N` of the valve, and through the groove and passa e O to the bottom of the bore B and beneat the hammer, such air suddenly raising the hammer until the entrance to the passage T in the bore is uncovered, when the air will exhaust through such passage. While the hammer is rising, the air above i-t exhausts through the passages p and P into the neck 'n4 of the valve-stem and thence through the passages Q and q to the outer air. As the hammer passes above the entrance in the bore of the passage S it permits the air beneath the valve to exhaust through such passage and the passage T until the valve is forced down by the live-air pressure on its'upper end, (the passage S being larger than the passage R, causing an exhaust more rapidly than the passage R can supply.)

' The valve reaches the position illustrated in Fig.- 1 in time to cause any cushioning that may be desired on the return stroke of the hammer by closing the passage lP and prearts being assumed, to be in the. position il ustrated in lFig. 1, live air is y admitted to the passage h4 by depressing the valve L, as by means of the thumb, and such venting further exhaust of the air above the piston; The cycle of 'operations above described is then repeated. y

It'will 'be observed 'that our hammer has the followingadvantages: There is no back 'pressure 'retard'ing the hammer during its working stroke, and as little cushoning as is -desired can be provided on the return stroke.

The valve is simple and strong and is held in both positions by live air, so that leakage cannot disturb its position. The valve is moved in both directions entirely by live air. These advantages cause the action of our tool to be extremely rapid.

It is obvious that changes can be made in the above-illustrated construction that will be withinthe scope of our invention. We desire not to be limited beyond the requirements of the prior art and the terms of our claims. l

Having thus described our invention, what we claim is- `1. In a pneumatic tool, the combination oi a casing having a bore for a hammer, a hammer, avalve, such tool having-alive-air passage that` is uncovered by the movement of the valve next following the Working stroke of the hammer, the air from suclvpassage serving to maintain the valve in the position then assumed and said passage being independent of those for supplying air to the hammer. A

2. In a pneumatic tool, the combination of a casing having a bore for a hammer, a hamvmer in such bore, a valve, a passage communicating with the under side of the valve and adapted to be uncovered by the hammer .as it .reaches-'the end of its working stroke, and a live-air passage adapted to be uncovered by the valve during the movement thereof caused by the air from the passage first mentioned said live-air passage being independentof those for supplyingair tothe hammer.

3. In a pneumatic tool, the combination of a valve having larger and smaller cylindrical portions and, having a neck formed in such smaller portion, saidlarger portion having a groove in its periphery that communicates with a bore in its stem, and a valve-casing having exhaust and supply ports that are adapted to be disconnected and connected by said smaller cylindrical portion of' the valve and said neck, respectively, `and an exhaust and supply p ort that is adapted to be IOO lIO

supplied through said groove, and exhausted portion of the valve.

4. In a pneumatic tool, the combination of a valve having larger and smaller cylindrical portions and having a neck formed in such by being uncovered by said larger cylindrical smaller portion, said larger portion having a groove in its periphery that communicates vwith a bore in its stem, and a valve-casing having exhaust and supply ports that are adapted' to be disconnected and connected' by l,said smaller cylindrical portion of vthe valve and said neck, respectively, and an exhaust andsupply port that is adapted to be supplied through said groove, and exhausted by being uncovered by said larger cylindrical portion of the valve, anda live-air passage y adapted to be covered vby rvsaid larger cylindrical'portion of the valve, inthe loivest po-V sition of the valve.

5. In a pneumatic tool, the -combination ofa casing having a bore for a hammer, a hammer, fa valve consisting of a stemhaving'a neck and a cylindrical head,`a jcasing in which. said valve is adapted to reciprocate, a supply-port for the upper end of said bore,

l and an exhaust-port therefor, that are adapt- A ed to be putin communication by said neck, or closed by said stem, anda supply and exhaust port for the lower end of'said bore that is adapted to -be supplied vby'a passage through said stem and-head and to bev exhausted by being uncovered by said-.head the @exhaust being .kept Aopen y throughout the {Working stroke of the hammer.

Y. 6,? I na 'pneumatic tool, the combination of -f va'casinghaving a bore fora hammer, a hammer, al valvegconsisting of a. stem having a neck andi a( lcylindrical head,..a casing in. Which. said valveis adapted to reciprocate, asupply-p'ortlfor the upper end of said bore,

-. and an exhaust-,port therefor, that are adapted to be put* in communication by said neck,

-or closed bysaid stem, a supply and exhaust port for the'lovver. end of said bore that is .adap'tcdto be'supplied by'a passage through saidstem land head-and to be exhaustedby being uncovered by said head, the exhaust being'kept open' throughout the Working stroke'of the hammer and-a passage adapted 4o to be uncovered by said hammer on its Work` y ed to be-put in 1communication by' said nec or closed by saidstem, a supply and exhaust portfor the lower end-fof said bore that is adapted-to be supplied by a passage through i said stem and head and4 toibe exhausted by being uncovered by said head, a passage adapted tofbe uncovered by said hammer on its Working stroke and communicating with thehead .end of' said val-'v efcas'ing t o supply air to shift the valve, and a live-air passage 6o adapted to be covered by said head in the 1 lowest position of the valve. that supplies air tothe valve to maintain the same in the positi'onfto which it is shifted. 5 i

In testimonythat we claim .the foregoing 65 We have 'hereunto setour hands.

" HAROLD A. RPRINDLE.'

JonuuAnoLrH v lWitnesses:l

HARRY REDEKKER, 4CARRIE REDEKER; 

